Yarn severing device for straight-bar knitting machines



y 2, 1956 A. J. COBERT 2,746,275

YARN SEVERING DEVICE FOR STRAIGHT-BAR KNITTING MACHINES Filed March 16, 1955 Ari/wk J. CoberZ.

INVENTOR i? ATTORNEY United States Patent 9 YARN SEVERING DEVICE FOR STRAIGHT-BAR KNITTING MACHINES Arthur J. Cobert, Signal Mountain, Tenn., assiguor of fifty per cent to Beautiful Bryans, Incorporated, Chattanooga, Tenn., a corporation of Tennessee Application March 16, 1953, Serial No. 342,699

Claims. (Cl. 66-145) This invention relates to a straight-bar or full-fashioned knitting machine and more particularly to such a machine in which there is provision of a means and method for severing the thread or yarn from the fabric being knitted, at the appropriate time.

In starting the operation of a knitting machine, the end of the yarn protruding from the yarn carrier tube must be held in some manner while the yarn carrier traverses across the needles. Thus, the yarn is fed from the carrier into the needles and the operation of knitting is commenced. As the fabric is formed in the knitting operation, it is gradually drawn away from the needles by a suitable fabric draw off mechanism as sucessive courses of the fabric are being knitted. As the fabric is drawn away, it is necessary to sever the yarn between the point at which its end is held and the first course of the fabric. Heretofore, the operation of severing the yarn from its point of initial attachment has been done manually by the operator of the machine. While such a procedure mighht be practical on small machines having only one or a very few knitting sections, it is not practical with machines now used in knitting mills having a large number of sections operating simultaneously under the control of one operator. Not only is it necessary to sever the yarn upon commencing the knitting operation, but it is also necessary to sever the yarn when the knitting operation is completed. It will be readily apparent that such maunal operations for a large number of knitting sections will require a large portion of the time of the operator. Since the cost of labor is a large part of the cost of operating a textile mill, it will be readily apparent that devices which reduce labor costs are highly desirable. Automatic devices for severing yarn which have been heretofore proposed have not been practical.

One object of my invention is to provide a yarn severing device for a straight-bar knitting machine which is simple and inexpensive in construction and etficient and reliable in operation.

Another object is to provide a means for and a method of severing the ends of the yarn from which a fabric is being knit comprising one or more hot wires held close to the edges of the fabric.

A further object of my invention is to provide a device for severing the yarn of which a fabric is being knit comprising an electrical resistance wire adapted to cut the yarn, the wire being movable from an inoperative to an operative position, a timing means for causing the movement of the wire into operative position at the proper time and for thus indirectly energizing the wire to cause it to sever the yarn at the proper instant.

The foregoing and other objects, features and advantages of this invention will be apparent from the following description and from the accompanying drawings of a preferred embodiment, it being understood that the detailed description and drawings are merely illustrative of the invention, which is defined in the claims.

In the drawings,

Figure 1 is a partial perspective view, partly diagrammatic, of one section of a straight-bar knitting machine, showing only those parts ofthe machine which areessential to a proper understanding of this invention.

Figure 2 is a symbolic representation of an electrical control panel used to control the operations of my machine.

Figure 3 is a symbolic representation of a variable resistor used in controlling the operation of my machine.

Like reference numerals refer to like parts throughout the several figures of the drawings.

According to my invention, one section of a straightbar knitting machine is illustrated. This section has a plurality of knitting needles 1, a plurality of sinkers and dividers 2, and a plurality of thread or yarn carriers, such as those illustrated at 3. A suitable yarn 4 extends from the yarn carriers 3 and is drawn from one or more of these carriers during the operation of knitting. The yarn is supplied to the yarn carriers from yarn cones, not shown.

The yarn is initially drawn from the yarn carriers by a suitable puller 5. The puller 5 also comprises means for holding the yarn at a point offset from the needle row 1. Features of applicants construction relating specifically to the construction and operation of the puller 5 form the subject matter of a separate application for Letters Patent in the United States Patent Oflice, Serial No. 363,591, filed June 23, 1953, entitled Thread Puller, Holder And Cutter. Further description of these parts is therefore omitted. During the operation of the knitting elements, a fabric 6 is formed and, as successive courses are knitted, the fabric is drawn away from the knitting elements by a draw off mechanism, such as a series of welt hooks 7. Such a mechanism is fully described in my application, Serial Number 294,804, filed June 21, 1952, and entitled Welt Turner.

When the fabric has been knitted sufficiently that its end will not tend to unravel, it is necessary to sever the end of the yarn from its point of attachment at 5. One or more means for doing this are provided. The means comprises a support arm or bracket 8, which is secured in an upright position in a suitable clamping member 9. The upper end of the support arm 8 is bent at a right angle and is slotted or formed like a fork, as at 8a, to receive a heating element 10. The clamp member 9 is fixed to a bracket 11, which, in turn, is fixed on a support rod 12 extending transversely across the knitting section and supported in suitable bearings in the frame 13 of the knitting machine.

A hook-shaped spring wire 14 is secured in a suitable manner to the clamp 9, as by means of a bolt 15. Suitable insulation 16 is provided to insulate the spring wire 14 from the clamp member 9 and from the bolt 15. A lead in wire 17 from one terminal of a variable resistor 18 is electrically connected to the spring wire 14.

The electrical resistance element 10 has a knot in one end and the element is passed into the slot 8a in the upper end of the support arm or bracket 8, the knot in the end of the element preventing its end from being drawn through the slot. The lower end of the electrical resistance element 16 is formed in the shape of a loop 19 designed to be hooked over the end of the hook-shaped spring wire 14. Thus, the spring wire 14 holds the electrical resistance element 16 taut and also provides an electrical conduit for the heating current. Another conductor 29 leads from ground to a bolt 21 on the clamping memher 9. By means of this conductor 20, the upper end of the electrical resistance element 10 is grounded, through the support arm or bracket 8, the clamp member 9, bolt 21 and the ground wire 26.

The other terminal of the resistor 18 is connected by a conductor 33 through and in series with an electrical switch 34 to the positive terminal of a suitable source of electric power, not shown. The switch 34 may conveniently be mounted on the support rod 12 for movement thereby to close the switch and thus the circuit 3 through the heating element 1 3 when the heating element is moved into engagement with the yarn 4. Conversely,

a when the element 19 is moved away from engagement with the yarn, the switch 34 is opened, thus breaking the circuit through the heating element 10. The negative terminal of the source of power is grounded and is thus connected, through thelead 20, to the upper end of the element It This provides a complete path for the passage of electricity through the element 10, in series with the variable resistor 18 and the switch 34.

The variable resistor 13 isadjusted to permit a voltage of suitable intensity to be applied across the resistance element 10, in order to heat that element to a temperature sufficient to sever quickly the yarn 4- at the appropriate time.

As heretofore mentioned, the brackets 11, supporting clamp members 9, brackets S and heating elements are fixed to a transverse rod 12 mounted rotatably in the rame 13 of the machine. Fixed to one outer end of the rod 12 is acam Wheel 23. This cam wheel has a notch 24 cut in its periphery for coaction' with a lug 25 on a wheel 26 supported on a spindle 27 from the frame 13 of the machine. The wheel 26 is adapted to be rotated, at suitable times, as by means of a belt 28 running around a pulley 29 at its other end. The pulley 29 is mounted on the axle of a suitable electric motor 30. The motor 30 is energized from a suitable source of power, not shown. A timer 22 is provided, of a conventional type, for closing and holdin-g closed, at predetermined times and for predetermined periods, the circuit through the lead-in wires 31 to the motor 30. Such timers are disclosed in U. S. Patent Number 161,008, 1,536,200, 1,890,200 and 2,432,110. The action of the parts is such that, at the appropriate moment, the timer 22 causes the motor 30 to be actuated to rotate the pulley 29, wheel 26 and lug 25,. When the lug 25 contacts the notch 24 in the wheel 23, the spindle 12'is rotated to move the heating elements 10 into contact with the yarn 4 between the fabric 6 and the point at which the yarn is held by the puller and holder 5. At this moment, the switch 34 is closed and causes I the variable resistor 18 and the electrical resistance element to be energized and the element is heated to a melting or burning temperature, thereby causing the yarn 4 to be severed. After the yarn is severed, the motor 30 is tie-energized by action of the timer 22 and a tension spring 32, connected between the support bracket 11 and the spindle. 27, draws the support bracket 11, rod 12, clamping member 9, bracket 8 and the heating element 10 back into a retracted position, at the same time opening the switch 34 and de-energizing the heating element 10.

By my invention, there is provided a simple, inexpensive method and means for severing the yarn used in knitting afabric. The method and means save considerable time on the part of an operator of such a machine and free the operator to operate more of these machines. This results in adirect saving in cost of labor.

The spring support 14 for the heating element 10 keeps the heating element taut when it becomes hot and expands. With this arrangement, the heating element can also be easily replaced, although such replacement is not often necessary;

The support arm or bracket 8 for the heating element forms a guard for the heating element wire which protectsthewire from inadvertent breakage or damage. This support bracket also forms a guard or shield which reduces the probability of the fabrics coming into contact With-.1116 heating element and thus affords a protection for the'fabric.

The heating elements 10 being supported at the appropriate spacing on; the rod 12, they are located at the ideal: spacing: from the edge of the fabric, so that when the yarn is. severed it; is cut at the proper spacing from theuedge of the fabric, neither too far away? nor too close tothefabric.

yarn extending from the fabric to the'yarn laying means,

means for holding said portion of the yarn at a point offset from the needle row, and yarn severing means including a bracket, a heating element wire mounted on the bracket, and a pring connected between the wire and bracket for holding the wire taut in the bracket.

2. in a full-fashioned knitting. machine, the combination of a needle row, means to lay yarn to said row, means cooperating with said' row' to knit fabric from saidv yarn and means to draw off the fabric, a portion of said yarn extending from the fabric to the yarn laying means, means for holding said portion of the yarn at a point. offset from the needle row, and yarn severing means including a supportingv bracket having a longitudinally extending guard portion, and a heating. element Wire mounted from the bracket at one side of said guard portion for severing. engagement with the held yarn.

3. In a full-fashioned knitting. machine, the combina tion of a needle row, means to lay yarn to said row, means cooperating with said row to knit fabric from said yarn and means to draw off the fabric, a portion of said yarn extending from the fabric to'the yarnlaying means, means for holding. said portion of the yarn at a point offset from the needle row, and yarn severing means including a heating element, a supporting bracket on which said heating element is supported in position for severing the held yarn, said bracket having a guard surface at that side of the heated element away from the held yarn, and means for heating said element to sever a yarn engaged therewith.

4. In a full-fashioned knitting machine, the combination of a needle row, means to lay yarn to said row, means cooperating with said row to knit fabric from said yarn and means to draw off the fabric, a portion of said yarn extending from the fabric to the yarn laying. means, means for holding said portion of the yarn at a point offset from the needle row, av yarn severing means comprising an element adapted to be heated to a temperature to sever the yarn, supporting means on which. said element is moved from and to an operative position to be contacted by said yarn as it extends from the fabric to said attachment means, actuating means for shifting the yarn severing means between said' operative and inoperative positions, and means to'heat said element toa predetermined temperature to sever the yarn.

5. In a full-fashioned knitting machine,v the combination: of aneedle row, means to lay yarn to said row,.means cooperating with said row to knit fabric from said yarn, and means to draw off the fabric, a portion of said yarn extending from. the fabric to the yarn laying means, means for holding said portion of the yarn at a point offset from the needle row, a supporting. bracket. and a heating element wire supported therein, the bracket being arranged to form a guard for the wire, a support on which said bracket is shiftable between an operative yarn engaging. position of said wire and a. withdrawn inoperative position,. and means for heating said element to sever the yarn.

References Cited in the file of this patent UNITE-Di STATES PATENTS 2,100,345 Miller- Nov. 30 1937 2,602313 Reading July" 8, I952 

